Silane and Fluorochemical Coated Glass Spheres

Solid glass imparts visual and material benefits that cannot be replicated when spheres are made of other materials such as ceramics or polymerics, aluminum oxides, or silicas and mineral fillers. Solid glass refracts [bends] and reflects light. Most ceramics [with exceptions] do not transmit light or exhibit specular [mirror-like] reflection due to their internal crystalline structures and surface irregularities. Instead of being reflected back, the light is “trapped” in the structure and emitted as diffuse or scattered reflectance, which is not as strong or direct as light transmitted through glass, which produces mirror-like reflectance. Prizmalite glass spheres distributed by Cospheric offer off the shelf pre-coated spheres for enhancing these effects.

Silane coated solid glass spheres with increased hydrophobicity are offered to improve the dispersion of spheres throughout paints and coatings. Silane coated spheres are not recommended for pure water solutions as the spheres will be too hydrophobic to wet.

Fluorochemical Coating is available for paint and coating applications where it is desired to bring the spheres to the top of the surface of the coating. This is best used in applications where retro reflectance is desired.

Density Marker Beads

Cospheric recently added density marker beads in aqueous solution to their range of products. Available in densities from 1.02 g/ml to 1.13 g/ml.

The beads come in a variety of colors and densities and ship within one business day. These beads are small microspheres of very specific particle density that are used to visualize density gradients. Commonly used in Percoll gradients these beads offer a fast visual indicator for scientists.

Cospheric Density Marker Beads are provided at a 20% concentration in an aqueous solution in 2.5ml vials. Unlike density marker kits which used to be manufactured by GE Healthcare and have been discontinued, the Cospheric’s colored microspheres are ready for use right out of the vial, don’t need to be swollen, will work with any media, do not expire, and do not change density over time.

Resources on Creating Density Gradients:

Biotechnology: Theory and Techniques, Volume I (Jones and Bartlett Series in Biology) by Jack Chirikjian and Chirikjian (Jan 1, 1995)
Pages 45-50 on Density Gradient Centrifugation.